Sweater Wizard is excellent -- I'm not sure if it's available for Mac though. I went to a workshop at my LYS that was a how-to on all the features, and it's amazing. Like it'll tell you how many yards of yarn your pattern will use as you configure it -- very handy.

Does any of this software show a PICTURE of what it will look like knitted up? I think this would be easy to do with today's softwware capabilities.
I checked out the one and it shows the pattern as you make it..but I didn't get to any step that will show the fnished facsimile.
Amybody know of one that will do that?